Cell shape changes and whole tissue movements are essential for the development of all metazoans. These morphogenetic processes must be precisely coordinated within the organism for development to proceed normally. The proposed research sets out to explore the hormonal regulation of imaginal disc morphogenesis during Drosophila metamorphosis. Drosophila provides an ideal model system for defining the spatial and temporal control of imaginal disc morphogenesis. Since the signal initiating this developmental event is known and there are vast resources available for gene discovery. In the proposed experiments, screens will be performed to identify genes required for imaginal disc morphogenesis. Mutants identified in these screens will be phenotypically characterized and a subset of the corresponding genes will be cloned and further analyzed for specific functions during imaginal disc morphogenesis. The proposed screens will provide a means to uncover the pathway that connects the hormonal signal to the force-generating molecules required for morphogenesis. In addition, the mechanisms that are defined by this research will provide insight into the regulation of morphogenesis in other higher organisms.